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Advanced search is divided into two main parts, and one or more groups in each of the main parts. The main parts are the "Search for" (including) and the "Remove from search" (excluding) part. (The excluding part might not be visible until you hit "NOT" for the first time.) You can add new groups to both the including and the excluding part by using the buttons "OR" or "NOT" respectively, and you can add more search options to all groups through the drop down menu on the last row (in each group).

For a result to be included in the search result, is it required to fit all added including parameters (in at least one group) and not fit all parameters in one of the excluding groups. This system with the two main parts and their groups makes it possible to combine two (or more) distinct searches into one search result, while being flexible in removing results from the final list.

OBJECTIVEHbA(1c) is strongly related to the development of diabetes complications, but it is still controversial which HbA(1c) level to strive for in the treatment of type 1 diabetes. The aim of the current study was to evaluate HbA(1c), followed from diagnosis, as a predictor of severe microvascular complications and to formulate HbA(1c) target levels for treatment.RESEARCH DESIGN AND METHODSA longitudinal observation study followed an unselected population of 451 patients diagnosed with type 1 diabetes during 1983-1987 before the age of 35 years in a region of Southeast Sweden. Retinopathy was evaluated by fundus photography and nephropathy data collected from medical records. HbA(1c) was measured starting from diagnosis and during the whole follow-up period of 20-24 years. Long-term weighted mean HbA(1c) was then calculated. Complications were analyzed in relation to HbA(1c) levels.RESULTSThe incidence of proliferative retinopathy and persistent macroalbuminuria increased sharply and occurred earlier with increasing long-term mean HbA(1c). None of the 451 patients developed proliferative retinopathy or persistent macroalbuminuria below long-term weighted mean HbA(1c) 7.6% (60 mmol/mol); 51% of the patients with long-term mean HbA(1c) above 9.5% (80 mmol/mol) developed proliferative retinopathy and 23% persistent macroalbuminuria.CONCLUSIONSLong-term weighted mean HbA(1c), measured from diagnosis, is closely associated with the development of severe complications in type 1 diabetes. Keeping HbA(1c) below 7.6% (60 mmol/mol) as a treatment target seems to prevent proliferative retinopathy and persistent macroalbuminuria for up to 20 years.

We thank Dr. Takahara (1) for the comment on our recent article exploring the impact of HbA1c, followed from diabetes onset, on the development of severe microvascular complications (2). As suggested, we have validated our results with Cox hazards analysis with severe microvascular events, i.e., laser-treated proliferative retinopathy and macroalbuminuria as a dependent variable and HbA1c (mmol/mol) as a time-dependent covariate.

In our article, we chose to analyze and present the results in a way that was perhaps easier for a clinician to interpret and apply in clinical routine. With life-table analysis we found that the incidence of both laser-treated proliferative retinopathy and macroalbuminuria increased sharply and occurred earlier with increasing long-term weighted mean HbA1c. In the same manner, the prevalence of microvascular complications increased steeply with higher long-term weighted mean HbA1c, categorized in different groups.

In conclusion, our study irrespective of statistical methods shows a strong association between development of late complications and long-term mean HbA1c, and keeping the average HbA1c below 7.6% (60 mmol/mol) seemed sufficient to prevent microvascular complications for at least up to 20 years.